Tire-valve stem



Aug- 1929- w. c. STEVENS TIRE VALVE STEM Filed Jan. 16. 1922 I inventor William (I S/e/e'ns TAHomeg Patented Aug. 6, 1929.

UNITED STATES PATENT OFFICE.

WILLIAM C. STEVENS, OF AKRON, OHIO, ASSIGNOR TO THE FIRESTONE TIRE AND RUBBER COMPANY, OF AKRON, OHIO, A CORPORATION OF OHIO.

TIRE-VALVE STEM.

Application filed January 16, 1922.

The subject matter of this application is a stem for valves of pneumatic tires, it being the object of the invention to produce a better and cheaper valve stem than has been manufactured heretofore. This invention relates to the valve stem as a new article of manufacture which may be manufactured in any suitable way, that described and claimed in Patent No. 1,506,457 granted August 26, 1924, being a practicable and operative method.

In the drawing accompanying this appli- 'ation is shown one form of my invention, it being understood that changes and modltications may be made in embodiments of'my invention. without departing therefrom, Within the fair scope of the appeiuled claim.

In the drawings:

Fig. 1 is a longitudinal section through a valve stem embodying the features of my invention, the usual removable valve mechanism, or insides being omitted, as they may be of any well known or standard construction, and illustration thereof is not deemed necessary. I

Fig. 2 is a cross section on the line 2 2 of Fig. 1.

The valve stem is formed with the usual barrel or stem 1, the outer surface of whi ch. is provided with the usual screw-threluled portions 2, and flattened areas The base or foot of the valve stem 41- is separated from the main body or barrel of the stem by the usual groove 5, and is provided on its upper face with the concentric grooves G which operate as a clamping means for the rubbeinner tube, the stem being provided with the usual nut, not shown. The upper or outer end .of the valve stem is formed with the interiorly and exteriorly threaded nipple 7 for the reception of the *alve iap and the threaded plug forming a part of the valve insides.

Valve stems in use prior to my invention have generally been made from a brass rod. which is machined to its final shape, which operation has necessitated the use of extensive and expensive screw machines and the employment ofskilled operators. One of the points wherein my improved form of valve stem differs from those which have preceded it, is that the valve stem is made of cast metal, preferably aluminum which die cast in molds under pressure. Much of Serial No. 529,558.

the surface of the stem can be formed in the casting operation, the remaining work being done by stamping, machining or by some other meclmnical operation. Aluminum will lend itself to this method of manufacture, and the resulting stem will. be lighter and cheaper than the usual brass stem now in use.

In the old form of valve stem, it is customary to form a ledge or seat some distance within the passageway, which seat forms a resting place for the light metal foot at the base of the usual valve insides. The spring of the alve mechanism is compressed be tween this foot and the screW-tln'eaded plug iitting within the nipple of the valve steni. In my improved valve stem the air passageway is indicated by the, numeral 8. The lower part of the passageway contains a light metal tube 9, the upper edge of which, indicated by the numeral 10, forms the seat for the foot of the valve mechanism. Any suitable means may be provided for keeping the tube in place in the valve stem, a suitable form of interlocking device being shown at 11. This interlock is formed by allowing some of the metal to How in around the lower edge of the tube and prevents the tube 9 from dropping into the inner tube of the tire. The tube 9 prevented from falling in the other direction by the valve insides. Any other suitable form of interlocking device may be employed if found suitable.

It will be seen. that by the substitution of cast metal, such as aluminum, the manufacture of valve stems may be cheapened and simplified. The machine work is reatly reduced over the old. methods and an improved article produced.

I claim:

A valve stem for use in pneumatic tires, comprising a cast metal body portion having a central longitudinal bore, the upper portion of which is conical and the lower portion cylindrical, a tube of uniform crosssection throughout its length mounted within the cylindrical portion of the said bore, and a shoulder integrally formed with the stem for retaining the tube in position, the said tube forming a ledge at a point midway of the bore to support the valve mecha nism.

WILLIAM C. STEVENS. 

